For cleaning a wooden deck, you'll be best served by using the lowest pressure setting that's still effective. For soft woods like cedar or pine, this is usually about 500 to 600 psi. For harder woods, it can go up to 1200 to 1500 psi.
The RYOBI 1800 PSI 1.2 GPM Electric Pressure Washer is the perfect powerful yet portable option to get the job done. This pressure washer is ideal for light duty applications like cleaning small driveways, sidewalks, decks, windows, patio furniture, campers, bikes, boats, and many other recreational applications.
For most deck surfaces 1500 pounds per square inch (PSI) is more than sufficient. The next step is to choose an appropriate fan degree for the nozzle. Typically decks will need anywhere from a 25-degree nozzle (for more stubborn build-up) to 40-degree (for newer decks with less damage or synthetic wood).
To clean a deck, some homeowners choose a washer with a pressure range of 1,300 to 2,400 psi, the same as washing a car. HGTV recommends working with the lowest pressure that cleans your deck materials gently: about 500 to 600 psi for soft woods like cedar or pine, and up to 1200 to 1500 psi for pressure-treated wood.
MEDIUM-DUTY pressure washers in the 1,800 to 2,000 PSI range can tackle bigger projects like large SUV's, RV's, siding and fencing, decks, garage floors and driveways.
There's no doubt that electric pressure washers from 1,300 to 2,300 psi can wash a concrete driveway, but it'll take longer. If you have a large driveway with lots of stains, you'll want more power to do the job faster.
Most electric pressure washers create 1300-1700 pounds per square inch of pressure (PSI) with a water flow of 1.5 gallons per minute (GPM), but experienced contractors recommend between 2000 and 3000 PSI and a flow of at least 2.5 GPM to clean dirty concrete effectively.
Applying Pressure
Although highly effective for cleaning concrete, applying this much pressure to your deck can cause irreversible damage. To clean a deck effectively, about 1,500 pounds of pressure will do the job nicely, without causing permanent damage.
Beware Pressure Washing Damage
If you have timber deck boards, a power washer's pressure may cause splintering and damage to the timber fibres. If the timber surface already has some splintering, pressure washing will only exacerbate the issue.
Concrete cleaning calls for powerful pressure washers featuring high pressure levels of 3000 PSI. However, if you will be using the power cleaner to maintain a range of surfaces in addition to concrete, choose one with adjustable pressure levels and set it to about 3000 PSI when you need to clean concrete.
This looks like very small raised wood grain fibers or hair on the decking boards. When you are prepping a deck you essentially remove a layer of oxidized or damaged wood cells. The more you need to remove, the greater the chance of making the wood look “fuzzy” or “soft”.
A pressure setting of 1500 psi should be strong enough to clean away deck stain. Hold the sprayer about 3 inches off the surface and move the sprayer as you work in the same direction as the grain.
If you're wondering whether pressure washing can damage wood, the short answer is yes, but only if you're not careful. That's why it's best to leave it to the professionals to pressure wash wood surfaces for you.
Removing exterior paint requires a stronger stream of pressure than soft washing jobs such as cleaning a roof. Thus, you want to find a pressure washer that is up to the task. To properly strip old paint, you will need a pressure washer with a psi of 2000 or higher. Even setting the unit at 2000 won't do the trick.
Concrete and asphalt require more cleaning power. You'll want to use the turbo nozzle on the 1600 PSI for hard-to-clean driveways, sidewalks, and patios as well as brick paving. For wood decks and painted surfaces, switch to the gentler 40-degree nozzle.
However, in general, a psi of 3000-4000 is commonly used for residential driveways.
The short answer is 48 hours. You should wait at least two days after pressure washing your deck before you consider staining it, to give time for it to dry. Now let's talk about specifics. Cleaning your deck is an all-important first step in the staining process.
A pressure washer is a straightforward machine that can clean very well with only water. However, it can ruin your deck if it's not used properly. This is a tool that is powerful enough to etch brick, but in the right hands, it can be gentle enough to wash siding.
Once you pressure wash your deck, it'll look like new timber again but it won't stay that way for long. If you like the grey look, then you could pressure wash to remove the grime then let it grey off again. It is best to seal it if you want it to last longer but you won't get that grey look.
Choosing a Pressure Washer
Vinyl siding can withstand a powerful gas pressure washer (2,500-3,000 psi). Aluminum, stucco or soft-grain wood homes will do better with a less powerful washer (about 1,200-1,500 psi). Determine whether you will rent or buy your machine.
PSI Pressure range for Different Surfaces
Different surfaces require different levels of PSI pressure. Generally, for most residential uses, an electric pressure washer (less than 2000 PSI) will suffice. Soft surfaces, such as decks and siding, usually require more cleaning power than harder surfaces such as driveways.
You have to know its capabilities, 1600 PSI is good for most home jobs (general siding cleaning/gutters, car washes, cleaning furniture) Don't expect it to clean a whole concrete driveway in one smooth pass.
For light-duty tasks such as washing a car or cleaning a barbecue grill, a pressure washer with 1,000 to 1,750 psi and 1.4 to 1.6 gpm (1,400 to 2,800 ECUs) will probably do the job.
1000-2000 PSI
Good for light cleaning jobs or for jobs where the surface to be cleaned is soft and easily damaged. This pressure range is good for cleaning decks and siding and for light-duty auto cleaning.
Any machine capable of producing at least 1,500 pounds per square inch (psi) of pressure can clean concrete, but the work will go much faster if you choose a model producing 2,500 to 3,000 psi, like the gas-powered option below.